Integrity Ratio: A Damage Mitigation Control Metric for Component Life Extension

Component life extension using control schemes involves a trade-off between vehicle maneuver performance and maneuver's impact on component life usage. In many cases, effective schemes are predicated on the availability of effective metrics in their evaluations. In this paper, a new metric, called the integrity ratio, is introduced to improve existing control schemes and guide the development of future ones. It contains information pertaining to component damage growth and maneuver performance and is evaluated using a surrogate model for damage prediction and a harmonic load limiting control scheme. Important findings indicate that limiting harmonic load with a higher integrity ratio helps to reduce damage growth while preserving vehicle maneuverability. A demonstration showcased that a reduction of 10% in damage growth can be achieved with less than a 1% change in maneuver. The utilization of the integrity ratio metric enables a holistic and less conservative damage-driven control strategy for extending the operational life of a component, compared to traditional methods such as load alleviation and load limiting.